Self-assembly of silica colloidal crystals by improved vertical deposition methods

The fabrication and characterization of silica colloidal crystal films self-assembled from suspension of monodisperse silica spheres are reported through different improvement on vertical deposition. Three vertical deposition methods on the crystal formation were compared in terms of microstructure and optical transmission measurements. The results show that both the temperature-controlled vertical deposition and the flow-controlled vertical deposition could gain closely packed structures as traditional method but with lower colloid consumption and shorter time of self-assembly. By adjusting the rate of solvent evaporation or the relative movement between the liquid-surface and substrate, it is possible to transfer monolayer or multilayer of silica colloidal crystals onto the substrates. The improved methods can be used for rapid deposition of high-quality colloidal crystal films over large surface area without any special equipment.